1. Field of the Invention
The present invention generally relates to a workpiece holding system which constitutes an improvement on my U.S. Pat. No. 5,019,129 which includes an adjustment screw in an adjustment block and a lock screw in the adjustment block alongside and spaced laterally of the adjustment screw with the lock mechanism providing a locking force which introduces a deflection in the adjustment block when the lock screw is rendered effective thereby introducing a small error. More specifically, the present invention is a workpiece holding system with lock screw in which the lock screw is placed axially in the center of the adjustment screw thereby eliminating any deflection and eliminating any small errors. Since the lock screw is already spring pressured on the adjustment screw, the increased pressure of the lock screw will not cause any change in the adjustment of the adjustment block and since the lock screw is oriented in the center of the adjustment screw, there will be no deflection of the adjustment block.
2. DESCRIPTION OF THE PRIOR ART
As indicated above, my U.S. Pat. No. 5,019,129 discloses an adjustment block in a workpiece holder with adjustment screws and lock screws for the adjustment block which are laterally spaced from the adjustment screws as illustrated in FIG. 1 of that patent. As also indicated above, the arrangement of the lock mechanism in the above mentioned patent can introduce a deflection in the adjustment block which can introduce small errors because the locking force is applied alongside the adjustment screws.
The prior art of record in the above mentioned patent does not disclose any structure equivalent to the arrangement of the lock screw axially along the center line of the adjustment screw as disclosed in this invention.
The following U.S. patents relate to various types of general purpose lock mechanisms.
U.S. Pat. Nos. 280,125 PA1 439,279 PA1 919,170 PA1 932,395 PA1 1,653,030 PA1 2,472,083
While the above patents disclose various types of lock nuts and other locking mechanisms for screw threaded members, none of the above patents disclose an arrangement equivalent to the arrangement of the adjustment screw and locking screw of this invention.